mines the same phil, when it went for service i asked them to check it out they told me it was standard as it is of damped design
i said 80ll0ck5, so they WD40d it, it was fine for a little while but its slower then ever, and only retuns flush when the boot is slammed shut, thats how slow its gone.
i keep telling myself to strip the thing apart but just not the time at mo, so its WD40 time me thinks, then i leave a bit of tissue in it to soak left overs up.